/* nag_sparse_nsym_basic_setup (f11bdc) Example Program.
 *
 * Copyright 2011, Numerical Algorithms Group.
 *
 * Mark 23, 2011.
 */

#include <nag.h>
#include <nag_stdlib.h>
#include <nagf11.h>
int main(void)
{
  /* Scalars */
  Integer                  exit_status = 0;
  double                   anorm, dtol, sigmax, stplhs, stprhs, tol;
  Integer                  i, irevcm, iterm, itn, j, la, lfill, lwork,
                           lwreq, m, maxitn, monit, n, nnz, nnzc, npivm;
  /* Arrays */
  char                     nag_enum_arg[100];
  double                   *a = 0, *b = 0, *wgt = 0, *work = 0, *x = 0;
  Integer                  *icol = 0, *idiag = 0, *ipivp = 0, *ipivq = 0,
                           *irow = 0, *istr = 0;
  /* NAG types */
  Nag_SparseNsym_Piv       pstrat;
  Nag_SparseNsym_Fact      milu;
  Nag_SparseNsym_Method    method;
  Nag_SparseNsym_PrecType  precon;
  Nag_NormType             norm;
  Nag_SparseNsym_Weight    weight;
  Nag_TransType            trans;
  Nag_SparseNsym_CheckData check = Nag_SparseNsym_NoCheck;
  NagError                 fail, fail1;

  INIT_FAIL(fail);
  INIT_FAIL(fail1);

  printf("nag_sparse_nsym_basic_setup (f11bdc) Example Program Results\n");
  /* Skip heading in data file */
  scanf("%*[^\n]");
  scanf("%ld%*[^\n]", &n);
  scanf("%ld%*[^\n]", &nnz);
  la = 3 * nnz;
  lwork = 200;
  if (
      !(a = NAG_ALLOC((la), double)) ||
      !(b = NAG_ALLOC((n), double)) ||
      !(work = NAG_ALLOC((lwork), double)) ||
      !(x = NAG_ALLOC((n), double)) ||
      !(wgt = NAG_ALLOC((n), double)) ||
      !(icol = NAG_ALLOC((la), Integer)) ||
      !(idiag = NAG_ALLOC((n), Integer)) ||
      !(ipivp = NAG_ALLOC((n), Integer)) ||
      !(ipivq = NAG_ALLOC((n), Integer)) ||
      !(irow = NAG_ALLOC((la), Integer)) ||
      !(istr = NAG_ALLOC((n + 1), Integer))
      ) {
    printf("Allocation failure\n");
    exit_status = -1;
    goto END;
  }

  /* Read or initialize the parameters for the iterative solver */
  scanf("%s%*[^\n]", nag_enum_arg);
  /* nag_enum_name_to_value(x04nac).
   * Converts NAG enum member name to value
   */
  method = (Nag_SparseNsym_Method) nag_enum_name_to_value(nag_enum_arg);
  scanf("%s%*[^\n]", nag_enum_arg);
  precon = (Nag_SparseNsym_PrecType) nag_enum_name_to_value(nag_enum_arg);
  scanf("%s%*[^\n]", nag_enum_arg);
  norm = (Nag_NormType) nag_enum_name_to_value(nag_enum_arg);
  scanf("%s%*[^\n]", nag_enum_arg);
  weight = (Nag_SparseNsym_Weight) nag_enum_name_to_value(nag_enum_arg);

  scanf("%ld%*[^\n]", &iterm);
  scanf("%ld%lf%ld%*[^\n]", &m, &tol, &maxitn);
  scanf("%ld%*[^\n]", &monit);

  /* Read the parameters for the preconditioner */
  scanf("%ld%lf%*[^\n]", &lfill, &dtol);
  scanf("%s%*[^\n]", nag_enum_arg);
  milu = (Nag_SparseNsym_Fact) nag_enum_name_to_value(nag_enum_arg);
  scanf("%s%*[^\n]", nag_enum_arg);
  pstrat = (Nag_SparseNsym_Piv) nag_enum_name_to_value(nag_enum_arg);

  /* Read the non-zero elements of the matrix A */
  for (i = 0; i <= nnz-1; i++)
    scanf("%lf%"NAG_IFMT "%ld%*[^\n]", &a[i], &irow[i], &icol[i]);

  /* Read right-hand side vector B and initial approximate solution */
  for (j = 0; j < n; j++)
    scanf("%lf", &b[j]);
  scanf("%*[^\n] ");
  for (j = 0; j < n; j++)
    scanf("%lf", &x[j]);
  scanf("%*[^\n] ");

  /* nag_sparse_nsym_fac (f11dac).
   * Incomplete LU factorization (nonsymmetric)
   */
  nag_sparse_nsym_fac(n, nnz, &a, &la, &irow, &icol, lfill, dtol, pstrat,
                      milu, ipivp, ipivq, istr, idiag, &nnzc, &npivm, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_sparse_nsym_fac (f11dac)\n%s\n", fail.message);
      exit_status = 1;
      goto END;
    }

  /* Initialize the solver using nag_sparse_nsym_basic_setup (f11bdc)
   * Real sparse nonsymmetric linear systems, setup routine
   */
  anorm = 0.0;
  sigmax = 0.0;
  nag_sparse_nsym_basic_setup(method, precon, norm, weight, iterm, n, m, tol,
                              maxitn, anorm, sigmax, monit, &lwreq, work,
                              lwork, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_sparse_nsym_basic_setup (f11bdc)\n%s\n",
             fail.message);
      exit_status = 2;
      goto END;
    }

  /* Call solver repeatedly to solve the equations.
   * Note that the arrays B and X are overwritten on final exit,
   * X will contain the solution and B the residual vector
   */
  irevcm = 0;
  lwreq = lwork;
  /* First call to nag_sparse_nsym_basic_solver (f11bec)
   * Real sparse nonsymmetric linear systems, solver routine
   * preconditioned RGMRES, CGS, Bi-CGSTAB or TFQMR method
   */
  nag_sparse_nsym_basic_solver(&irevcm, x, b, wgt, work, lwreq, &fail);
  while (irevcm != 4) {
    switch (irevcm) {
    case -1:
      /* nag_sparse_nsym_matvec (f11xac)
       * Real sparse nonsymmetric matrix vector multiply
       */
      trans = Nag_Trans;
      nag_sparse_nsym_matvec(trans, n, nnz, a, irow, icol, check, x, b,
                             &fail1);
      break;
    case 1:
      trans = Nag_NoTrans;
      nag_sparse_nsym_matvec(trans, n, nnz, a, irow, icol, check, x, b,
                             &fail1);
      break;
    case 2:
      /* nag_sparse_nsym_precon_ilu_solve (f11dbc)
       * Solution of real linear system involving incomplete LU
       * preconditioning matrix
       */
      trans = Nag_NoTrans;
      nag_sparse_nsym_precon_ilu_solve(trans, n, a, la, irow, icol, ipivp,
                                       ipivq, istr, idiag, check, x, b,
                                       &fail1);
      break;
    case 3:
      /* nag_sparse_nsym_basic_diagnostic (f11bfc)
       * Real sparse nonsymmetric linear systems, diagnostic routine
       */
      nag_sparse_nsym_basic_diagnostic(&itn, &stplhs, &stprhs, &anorm,
                                       &sigmax, work, lwreq, &fail1);
      printf("\nMonitoring at iteration no.%4ld\n", itn);
      printf("residual norm:%14.4e\n\n", stplhs);
      printf("%16s%16s\n","Current Sol","Current Res");
      for (i = 0; i < n; i++)
        printf("%16.4e%16.4e\n", x[i], b[i]);
      printf("\n");
    }
    if (fail1.code != NE_NOERROR) irevcm = 6;
    /* Next call to nag_sparse_nsym_basic_solver (f11bec) */
    nag_sparse_nsym_basic_solver(&irevcm, x, b, wgt, work, lwreq, &fail);
  }
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_sparse_nsym_basic_solver (f11bec)\n%s\n",
             fail.message);
      exit_status = 3;
      goto END;
    }

  /* Obtain information about the computation using
   * nag_sparse_nsym_basic_diagnostic (f11bfc).
   */
  nag_sparse_nsym_basic_diagnostic(&itn, &stplhs, &stprhs, &anorm, &sigmax,
                                   work, lwreq, &fail);
  if (fail.code != NE_NOERROR)
    {
      printf("Error from nag_sparse_nsym_basic_diagnostic (f11bfc) \n%s\n",
             fail.message);
      exit_status = 4;
      goto END;
    }
  /* Print the output data */
  printf("Final Results\n");
  printf("Number of iterations for convergence:     %5ld\n", itn);
  printf("Residual norm:                            %14.4e\n", stplhs);
  printf("Right-hand side of termination criterion: %14.4e\n", stprhs);
  printf("1-norm of matrix A:                       %14.4e\n", anorm);
  /* Output x */
  printf("\n%16s%16s\n","Solution","Residual");
  for (i = 0; i < n; i++)
    printf("%16.4e%16.4e\n", x[i], b[i]);
  printf("\n");
 END:

  if (a) NAG_FREE(a);
  if (b) NAG_FREE(b);
  if (work) NAG_FREE(work);
  if (x) NAG_FREE(x);
  if (wgt) NAG_FREE(wgt);
  if (icol) NAG_FREE(icol);
  if (idiag) NAG_FREE(idiag);
  if (ipivp) NAG_FREE(ipivp);
  if (ipivq) NAG_FREE(ipivq);
  if (irow) NAG_FREE(irow);
  if (istr) NAG_FREE(istr);

  return exit_status;
}